Various communication devices have been used to enable remote access and control of a motor vehicle. For example, short-range and medium-range wireless RF communication devices have been used to activate door locks, to start the engine, to access vehicle status information, and so forth. The communication device can be in the form of a so-called “smart key fob” or a nomadic device (such as a cell phone or PDA) equipped with an RF transceiver in the form of a SDIO card for example, as described in the U.S. Pat. No. 7,224,262 to Simon et al. Another approach, described for example in the U.S. Pat. No. 6,970,703 to Fuchs et al., is to configure both the vehicle and the user-borne nomadic device for both short-range RF communication and global network communication. In that case, the short-range RF communication link is used for remote access and control if the nomadic device is within a prescribed range of the vehicle; and otherwise, the global network communication link is used.
The above-described approaches all have significant drawbacks. For example, smart key fobs tend to be both too large and too expensive when human-machine interface (HMI) devices such as keypads and displays are integrated into the fob. And localizing all of the vehicle information and control functionality into a single special-purpose nomadic device is also undesirable because many users frequently change nomadic devices as new styles, features and functions become available, and because all functionality is lost if the nomadic device is lost or fails, or has a discharged battery. Accordingly, what is needed is an improved and lower-cost way of achieving both medium-range and long-range communication and control for a vehicle.